Ukraine's president agrees 'joint and concerted action' with Blinken ahead of Putin-Biden call: tweet

Ukrainian President Volodymyr Zelenskiy spoke to U.S. Secretary of State Antony Blinken and agreed to continue "joint and concerted action" ahead of U.S. President Joe Biden's call with Russian President Vladimir Putin, Zelenskiy said on Monday.

Ukraine has accused Russia of massing tens of thousands of troops near its border in preparation for a possible large-scale military offensive. Russia has dismissed talk of a new assault on Ukraine as false but told the West not to cross its "red lines" and to halt the eastward expansion of the NATO alliance.

"Agreed to continue joint & concerted action. Grateful to U.S. strategic partners & allies for the continued support of our sovereignty & territorial integrity. Nothing about Ukraine without Ukraine," Zelenskiy tweeted.